LAG-3 Recombinant Protein Antigen
Novus Biologicals, part of Bio-Techne | Catalog # NBP1-85781PEP
Key Product Details
Source
E. coli
Tag
N-terminal His6ABP (ABP = Albumin Binding Protein derived from Streptococcal Protein G)
Conjugate
Unconjugated
Applications
Antibody Competition
Product Specifications
Description
A recombinant protein antigen with a N-terminal His6-ABP tag corresponding to human LAG3.
Source: E. coli
Amino Acid Sequence: LVTGDNGDFTLRLEDVSQAQAGTYTCHIHLQEQQLNATVTLAIITVTPKSFGSPGSLGKLLCEVTPVSGQERFVWSSLDTPSQRSFSGPWLEAQEAQLLSQPWQCQLYQGERLLGAAVYFTELSSPGAQ
Fusion Tag: N-terminal His6ABP (ABP = Albumin Binding Protein derived from Streptococcal Protein G)
This product is intended to be used as a blocking antigen for antibody competition assays. Any other use of this antigen is done at the risk of the user. The use of this product for commercial production is strictly prohibited. Please contact technical support if you have any questions.
Purity
>80% by SDS-PAGE and Coomassie blue staining
Predicted Molecular Mass
32 kDa.
Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
Applications
Antibody Competition (10 - 100 molar excess)
Application Notes
This recombinant antigen is only intended to be used as a blocking agent to confirm antibody specificity with the corresponding antibody, catalog number NBP1-85781.
It is purified by IMAC chromatography, and the expected concentration is greater than 0.5 mg/ml.
For current lot information, including availability, please contact our technical support team click nb-technical@bio-techne.com
For further blocking peptide related information and a protocol, click here.
Protein / Peptide Type
Recombinant Protein Antigen
Formulation, Preparation and Storage
NBP1-85781PEP
| Formulation | PBS and 1M Urea, pH 7.4. |
| Preservative | No Preservative |
| Concentration | Please see the vial label for concentration. If unlisted please contact technical services. |
| Shipping | The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below. |
| Stability & Storage | Store at -20C. Avoid freeze-thaw cycles. |
Background: LAG-3
As mentioned above, LAG-3 binds to MHCII and this occurs via a proline-rich amino acid loop in D1 (1, 3). Another unique feature of LAG-3 is the longer connecting peptide region between the D4 and the transmembrane, which is acted upon and cleaved by metalloproteinases a disintegrin and metallopeptidase domain (ADAM) 10 and ADAM17 to generate a soluble 54 kDa form of LAG-3 (sLAG-3) (1, 3). The interaction of LAG-3 with MHCII prevents the MHC molecule from binding to a T-cell receptor (TCR) or CD4, thereby functioning in an inhibitory role and suppressing the TCR signal (4). When LAG-3 crosslinks with the TCR/CD3 complex, it causes reduced T-cell proliferation and cytokine secretion (4). This negative regulation is important in controlling autoimmunity as one study found Lag3-/- NOD (non-obese diabetic) mice had accelerated diabetes onset and increased T-cell infiltration into islet cells (5). On the other hand, besides being a negative regulator of T-cells, LAG-3 binding to MHCII molecules on APCs induces dendritic cell maturation and cytokine secretion by monocytes (5, 6). In addition to MHCII, other reported ligands for LAG-3 includes fibrinogen-like protein 1 (FGL1), liver endothelial cell lectin (lSECtin), galectin-3 (Gal-3), and alpha-synuclein fibrils (1). Gal-3, for instance, is expressed on stromal cells and CD8+ T-cells in the tumor microenvironment and the interaction with LAG-3 was shown to be crucial for the suppression of secreted cytokine IFN-gamma and may control anti-tumor immune responses (1, 5). Interestingly, a mouse model of Parkinson's disease revealed LAG-3 binding to alpha-synuclein fibrils in the central nervous system, contributing to its pathogenesis (1, 5).
Recent cancer immunotherapeutic approaches have focused on inhibitory receptors such as LAG-3 to revive expression of cytotoxic T-cells to attack tumors (6). LAG-3 has been shown to be co-expressed and have synergy with another immune-checkpoint molecule called programmed-death 1 (PD-1) (1, 4, 5, 6). In a mouse model of colon adenocarcinoma LAG3 blockade alone was largely ineffective, however co-blockade of LAG-3 and PD-1 limited tumor growth and resulted in tumor clearance in 80% of mice, compared to 40% with PD-1 blockade alone (5). Additionally, in a model of fibrosarcoma the LAG-3/PD-1 duel blockade increased survival and the percentage of tumor-free mice (5). Analysis of a variety of human tumor samples (e.g. melanoma, colon cancer, head and neck squamous cell carcinoma) also suggest that LAG3 alone and combinatorial treatment with PD-1 may be a good target for treatment (1, 3-6). To date there are over 10 different agents targeting LAG-3 in clinical trials for cancer either as an anti-LAG-3 blocking antibody monotherapy or as a combination antagonist bispecific antibody, primarily with PD-1 (1, 3-6).
Alternative names for LAG-3 includes 17b4 lag3, 17b4 neutralizing, 17b4, CD223, FDC, LAG-3 17b4, LAG-3 blocking, and LAG3.
References
1. Maruhashi, T., Sugiura, D., Okazaki, I. M., & Okazaki, T. (2020). LAG-3: from molecular functions to clinical applications. Journal for Immunotherapy of Cancer, 8(2), e001014. https://doi.org/10.1136/jitc-2020-001014
2. Triebel, F., Jitsukawa, S., Baixeras, E., Roman-Roman, S., Genevee, C., Viegas-Pequignot, E., & Hercend, T. (1990). LAG-3, a novel lymphocyte activation gene closely related to CD4. The Journal of experimental medicine, 171(5), 1393-1405. https://doi.org/10.1084/jem.171.5.1393
3. Ruffo, E., Wu, R. C., Bruno, T. C., Workman, C. J., & Vignali, D. (2019). Lymphocyte-activation gene 3 (LAG3): The next immune checkpoint receptor. Seminars in immunology, 42, 101305. https://doi.org/10.1016/j.smim.2019.101305
4. Long, L., Zhang, X., Chen, F., Pan, Q., Phiphatwatchara, P., Zeng, Y., & Chen, H. (2018). The promising immune checkpoint LAG-3: from tumor microenvironment to cancer immunotherapy. Genes & cancer, 9(5-6), 176-189.
5. Andrews, L. P., Marciscano, A. E., Drake, C. G., & Vignali, D. A. (2017). LAG3 (CD223) as a cancer immunotherapy target. Immunological reviews, 276(1), 80-96. https://doi.org/10.1111/imr.12519
6. Goldberg, M. V., & Drake, C. G. (2011). LAG-3 in Cancer Immunotherapy. Current topics in microbiology and immunology, 344, 269-278. https://doi.org/10.1007/82_2010_114
Long Name
Lymphocyte-activation Gene 3
Alternate Names
CD223, LAG3
Gene Symbol
LAG3
Additional LAG-3 Products
Product Documents for LAG-3 Recombinant Protein Antigen
Product Specific Notices for LAG-3 Recombinant Protein Antigen
This product is for research use only and is not approved for use in humans or in clinical diagnosis. This product is guaranteed for 1 year from date of receipt.
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